Amtrak's president was fired Wednesday by the company's board of directors, who said David Gunn did not drive the debt-laden rail service fast enough toward major changes.

Democrats criticized Gunn's ouster and questioned whether the firing was legal, contending it was part of a Bush administration effort to kill national rail service.

As Amtrak's president and chief executive, Gunn struggled to maintain service amid a sinking financial picture and a push by the White House and some in Congress to transform the railroad into a group of companies offering regional service.

Gunn was offered the chance to resign; he refused.

Amtrak's board chairman, David Laney, praised Gunn's effort to put Amtrak in good working order, but said the company's needs went further.

"That is not acceptable. We're more ambitious than that," Laney said. "We just need to change gears."

Laney said it was a gradually worsening relationship between Gunn and the board, not any single disagreement, that led to his ouster.

Gunn took over in 2002 after having headed transit systems in New York City, Washington and Toronto. Amtrak declined to make Gunn available or provide information about how he could be contacted.

Rep. John Mica, R-Fla., said Gunn was fired because of a clash over the board's vote in September to authorize splitting off the Northeast Corridor, an idea the administration supported. The Washington-Boston service accounts for the largest share of the railroad's ridership.

"David Gunn bucked that idea, so that was the straw that broke the camel's back," said Mica, a member of the House Transportation and Infrastructure subcommittee on railroads.

"He's a very capable operational manager, but he wasn't willing to go along with the dramatic changes that need to be made," Mica said.

Sen. Charles Schumer, D-N.Y., praised Gunn as "a brilliant manager" and said his firing "decapitated Amtrak."

Schumer and other Democrats said the removal may have been illegal because the seven-member board has three vacancies while two members serve by recess appointment.

Laney said the board has the authority to act as it did.

"David's a very popular guy and I understand some of the responses are very emotional, but unfortunately they're without substance," he said.

Rep. James Oberstar of Minnesota, the top Democrat on the full committee, said he would seek to have Gunn testify next week at a House hearing.

Other lawmakers criticized Gunn as a roadblock to overhauling national rail service.

"I am hopeful that new leadership can open the door for Amtrak to work closely with Congress to achieve meaningful reforms," said Rep. John Sweeney, R-N.Y.

Amtrak has never made money in its 34-year history. An operating loss of more than $550 million was expected for the budget year that ended Sept. 30. The railroad has a debt of more than $3.5 billion.

The White House has called for an end to subsidies for Amtrak, but the House has approved an appropriation of nearly $1.2 billion for this budget year.

In recent months, Amtrak has been besieged by problems up and down the line, from equipment breakdowns to big-ticket budget woes.

Earlier this year, Amtrak suspended all high-speed Acela service between Washington, New York City, and Boston, due to cracks discovered in the brakes.

A report issued last week by the Government Accountability Office, the auditing arm of Congress, said Amtrak needs to improve the way it monitors performance and oversees its finances in order to reach firm financial footing.

"The company is likely to need outside help in developing a comprehensive approach to address internal control weaknesses and improve the financial information for management and external stakeholders," the report found.

Transportation Secretary Norman Y. Mineta, who also sits on Amtrak's board, said the report was "unusual, if not unprecedented, in the scope of its review and the severity of its indictment." He urged the board to "stop and take a fresh look on how to proceed in the face of this nonpartisan, objective report of systemic failure."